| 1. General Composition | | | | coatings, explosives,... Cellulose is without a doubt one |
| Wood is build primarily out the following compounds | | | | of the most important and versatile products for the |
| (in % dry weight): | | | | economy! |
| - cellulose 40-50% | | | | 3. Lignine |
| - lignin: 16-25% in hardwood - 23-33% in softwood | | | | Lignine is an organic polymer, typically found in wood. |
| - hemi-cellulose: 20-30% in hardwood - 15-20% in | | | | Softwood contains more lignine as hardwood. It is |
| hardwood | | | | build from giant, 3-dimensional molecules of a complex |
| - other compounds (water, resins,...) 5-30% | | | | composition. It is a dark compound that is a waste |
| - minerals 0,1-3% | | | | product from the paper industry. 4. Hemi-cellulose |
| The actual structure of wood is formed by the | | | | Hemi-cellulose is closely related to cellulose. They are |
| fiberlike structure of cellulose (and hemi-cellulose). | | | | both structures build from glucose. But hemi-cellulose |
| Lignin forms the binding agent between these | | | | contains also other types of sugar molecules in its |
| fiberlike structures. | | | | structures. The fibers are also shorter then those of |
| 2. Cellulose | | | | cellulose, only a few hundreds of sugar molecules. |
| Cellulose is one of the most abundant organic | | | | Hard wood contains more hemi-cellulose then |
| compounds on earth. Not only woody plants like | | | | softwood. |
| trees are build from it but also all other plants. Cotton | | | | 5. other substances and minerals |
| fibres are made of cellulose, wood consists for about | | | | There are other organics compounds in wood that |
| 50% out of cellulose. One cellulose molecule is a chain | | | | don't have constructive properties. But they |
| of thousands of glucose molecules. In it's pure form it | | | | contribute to color, odor, strength and mass. Oils and |
| is a white fibre. Cellulose for paper production is | | | | fatty molecules, wax, starch,... are some examples. |
| normally harvested from wood but some plants are a | | | | Besides these organic substances, wood contains also |
| good source as well. Cellulose is also used in the | | | | anorganic minerals like calcium, natrium and |
| chemical industry as a basic material for the | | | | magnesium in the form of phosphates, silicates, |
| production of synthetic products like tissues, | | | | sulphates,... |